This invention relates to acid-dyeable polymer compositions suitable for use in manufacturing fibers, fabrics, films and other useful articles, and to the articles and methods of making such compositions and articles. This invention also relates to processes for preparing the polymeric additive composition and using it to produce acid-dyeable polymer compositions.
Polyesters, especially polyalkylene terephthalates, have excellent physical and chemical properties and have been widely used for resins, films and fibers. In particular, polyester fibers have a high melting point, and can attain high orientation and crystallinity. Accordingly, polyesters have excellent fiber properties such as chemical, heat and light stability, and high strength. However, polyesters, especially polyester fibers and fabrics, are difficult to dye. The molecular structure and the high levels of orientation and crystallinity that impart the desirable properties to the polyester also contribute to a resistance to coloration by dye compounds. Also contributing to the difficulty in dyeing polyester compositions is the characteristic that polyesters do not have dye sites within the polymer chain that are reactive to basic or acid dye compounds.
Nylon polymers are generally dyed more easily than polyesters because of their greater permeability and, in the case of the preferred acid dyes, because the amine end groups in nylon serve as dyesites. However, in many cases these amine-end dyesites are not present at sufficiently high concentration to give the desired depth of dyeing, particularly in fine-denier fibers. Therefore, improvements in the acid dyeability of nylon are desired.
To impart acid dyeability to polyester, it has been proposed to blend polyester with nylon 6 or nylon 6,6 to obtain the benefits of the amine-end dyesites in the resulting polyester/polyamide copolymer composition. The high concentrations of polyamide that may be required to impart dyeability in this polyester/polyamide composition can result in forming polyamide microfibrils, which decrease the physical properties of the polyester/polyamide copolymer and create difficulties in processing.
Co-polymerizing nitrogen containing compounds into polyester chains to improve acid dyeability has been disclosed in, for instance, U.S. Pat. Nos. 3,901,853, 4,001,189 and 4,001,190.
Canadian Patent No. 974,340 discloses acid-dyeable polyester compositions comprising tertiary nitrogen-containing polyamides. Preferred are copolyamides of two or more monomers inclusive of diamines, dicarboxylic acids and aminocarboxylic acids. The tertiary nitrogen component may be derived from piperazine derivatives; HOOC(xe2x80x94CH2)nxe2x80x94NRxe2x80x94(CH2)nxe2x80x94COOH, wherein R can be a group selected from the class consisting of aliphatic (branched or unbranched), cycloaliphatic, aryl or heterocyclic groups; R1xe2x80x94NHxe2x80x94R2xe2x80x94NR3xe2x80x94R4xe2x80x94NHR5, wherein R2 and R4 can be a group selected from aliphatic (branched or unbranched), cycloaliphatic or aryl, R1 and R5 can be a group selected from hydrogen, aliphatic (branched or unbranched), cycloaliphatic or aryl, and R3 is aliphatic (branched or unbranched), cycloaliphatic, aryl or heterocyclic; and cyclic polyamines. Piperazine ring containing polyamides are preferred and all of the examples are directed to these compounds, and to their use with polyethylene terephthalate or polybutylene terephthalate. Piperazine ring containing polyamides, a cyclic compound containing two nitrogens on a single ring, is not sufficiently thermally stable for many applications.
WO 01/34693 (corresponding to co-pending U.S. patent application Ser. No. 09/708,209 filed Nov. 8, 2000, now U.S. Pat. No. 6,576,340, filed Aug. 11, 2000 (Docket No. RD-7850)), discloses an acid-dyeable polyester composition made by melt-blending a polyester with a polymeric additive containing a secondary amine salt or a secondary amine, such as made by combining bis(hexamethylene)triamine with a second monomer unit such as aterephthalate. This technology is particularly useful for dyeing fabrics lightly, but adding 3-4 mole % or more of the dye has been found to impact physical properties, particularly tenacity. Tenacity is improved by adding phosphorous acid; however, phosphorous acid leads to instability of pack pressure and may cause spin problems over the long run. In addition, it was not possible to significantly increase the amount of BHMT added using phosphorus acid without spin problems. Therefore, an additive that can provide deep dyeable polyester with acid dyes without such drawbacks is desired.
All of the aforementioned documents are incorporated herein by reference.
It is desirable to have acid-dyeable nitrogen-containing polyester and/or nylon compositions with good physical properties which may be easily processed into fibers, films or other shaped articles and acid-dyed without expensive additives, special solutions, spinning problems, and/or complicated application procedures. It is particularly desirable to be able to deep dye such compositions or shaped articles.
The invention is directed to an acid-dyeable polymer composition comprising (a) polymer and (b) polymeric additive comprising repeating units having the formula: 
or salts thereof, wherein A, B and Q, which may be the same or different, are selected from aliphatic or aromatic substituents provided that at least four carbon atoms separate any two nitrogen groups, R is an aliphatic or aromatic group, a is 1 to 5, and n is 3 to about 1,000.
In one preferred embodiment, a is 1. In another preferred embodiment, a is greater than 1, preferably 2-5.
In one preferred embodiment, the polymer is polyester, preferably selected from the group consisting of polyalkylene terephthalate, polyalkylene isophthalate and polyalkylene naphthalate and copolyesters thereof and blends thereof, more preferably selected from the group consisting of polyethylene terephthalate, polytrimethylene terephthalate, polytetramethylene terephthalate and copolyesters thereof and blends thereof. One preferred polymer is polytrimethylene terephthalate.
In another preferred embodiment, the polymer is nylon. Nylon is acid-dyeable and the invention makes it possible to deep-dye nylon. For instance, with this invention it is possible to prepare nylon compositions, fibers and other products which can be dyed to a deep shade. Preferred nylons include nylon 6, nylon 4,6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 12,12 and copolymers and blends thereof. Most preferred are nylon 6 and nylon 6,6.
Preferably, A, B and Q are selected from alkylene substituents containing from 4 to 20 carbons and arylene substituents containing from 6 to 18 carbons. More preferably, R is C1-C8 alkyl, and A and B are preferably C4-C8, alkylene and Q is preferably C2-C10 alkylene.
Preferably the polymeric additive is prepared by polymerizing (i) polyamine containing tertiary amine unit(s) or salts thereof and (ii) other monomer units, and the polyamine is selected from those having the formula: H2N(CH2)x[NR(CH2)y]aNH2 or salts thereof, wherein x and y, which may be the same or different, are 4 to 10, a is 1 to 5, and R is an alkyl group containing 1 to 8 carbons in a straight or branched chain. In one preferred embodiment, a is 1. In another preferred embodiment, a is greater than 1, preferably 2-5.
Preferred polyamines include methyl-bis(hexamethylene) triamine, methyldibutylenetriamine, and dimethyltributylenetetramine or salts thereof.
Preferably the polymeric additive is prepared by polymerizing (i) polyamine containing tertiary amine unit(s) or salts thereof and (ii) aliphatic and aromatic dicarboxylic acids or esters. Preferred aliphatic and aromatic dicarboxylic acids or esters include dimethyl adipate, adipic acid, dimethyl terephthalate, terephthalic acid, dimethyl isophthalate, isophthalic acid, dimethyl naphthalate, naphthalic acid, or mixtures thereof. More preferred are dimethyl adipate, adipic acid, dimethyl terephthalate, terephthalic acid, or mixtures thereof. Most preferred are dimethyl adipate, dimethyl terephthalate, or mixtures thereof.
In one preferred embodiment, the tertiary amine of the polymeric additive is partly or completely salinized with phosphorous acid, phosphoric acid, pyrophosphoric acid or phenyl phosphinic acid. In another preferred embodiment, the polymeric additive is not a salt.
Preferably, n is from 3 to about 100, more preferably 3 to about 20.
Preferably, the composition is prepared by melt blending the polymer and the polymeric additive.
In preferred embodiments, the composition is an acid-dyeable polyester or nylon composition and the acid-dyeable polyester or nylon composition is prepared by melt blending the polyester and the polymeric additive. Preferably, the composition comprises (I) the nylon or the polyester and (II) a block or random copolymer prepared from (a) the polyester or the nylon and (b) the polymeric additive; and the amount of tertiary amine units is effective to promote or improve acid-dyeability.
Preferably, the composition contains at least about 6 moles tertiary amine units/per million grams of the polymer composition (mpmg). This amount will be sufficient to improve dyeability of nylons and other polymers.
When more than minor changes are desired, the composition preferably contains about 44 or more moles tertiary amine/per million grams of the resulting polymer (mpmg), even more preferably about 88 or more mpmg, and most preferably about 132 mpmg or more, and preferably the composition contains up to about 480 mpmg, more preferably up to about 322 mpmg and most preferably up to 240 mpmg.
The composition may be in the form of a shaped article, preferred embodiments including fiber, film or film layer. One preferred fiber is a monocomponent fiber. Other preferred fibers include multicomponent fibers, such as a component of a bicomponent fiber. In one preferred embodiment, the composition is in the form of at least one component of a bicomponent fiber comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) components.
The invention is also directed to an acid-dyed composition and a process of acid dyeing the composition or articles made therewith.
The invention is also directed to a process for preparing an acid-dyeable polymer composition.
The invention is further directed to a process for the preparation a polymer compound with repeating units having the formula: 
or salts thereof, wherein A, B and Q, which may be the same or different, are selected from aliphatic or aromatic substituents provided that at least four carbon atoms separate any two nitrogen groups, R is an aliphatic or aromatic group, a is 1 to 5, and n is 3 to about 1,000, the process comprising (1) polymerizing (a) polyamine containing secondary amine unit(s) or salts thereof and (b) aliphatic or aromatic dicarboxylic acids or esters, to form a polyamide, and (b) alkylating secondary amine units of the polyamide. Alkylation forms form the tertiary amine portion (NRxe2x80x94B). In one preferred embodiment, the alkylation comprises methylating under acidic conditions using formaldehyde and formic acid.
By xe2x80x9cacid-dyeablexe2x80x9d it is meant that the composition itself, or fiber, fabric, film or any other article (e.g., shaped articles) made with the composition has an affinity for acid dyes.
The polymer composition preferably comprises either polyesters or nylons, or blends of one or more of these.
Reference to a polymer should be understood to mean a single polymer or blends or mixtures of such a polymer. In other words, xe2x80x9cpolyesterxe2x80x9d means one or more polyesters. Thus, for instance, if applicant refers to a composition containing x mole % of a polyester, the composition may comprise x mole % of one polyester or x mole % total of different polyesters. Similarly, xe2x80x9cpolymeric additivexe2x80x9d means one or more polymeric additives.
One preferred class of polymers is polyesters. By xe2x80x9cpolyesterxe2x80x9d or xe2x80x9ca polyesterxe2x80x9d, applicant is referring to a single polyester, and/or to blends or mixtures of polyesters. The preferred polyesters are polyalkylene terephthalates, polyalkylene naphthalates and polyalkylene isophthalates, and polyalkylene terephthalates are most preferred. More preferred are polyethylene terephthalates, polytrimethylene terephthalates and polytetramethylene terephthalates, and polytrimethylene terephthalates are most preferred.
The Mn for the polyester (e.g., polyalkylene terephthalate) is preferably at least about 15,000, more preferably at least about 18,000, and is preferably about 40,000 or less, more preferably about 35,000 or less. The preferred Mn depends on the polyester used. The most preferred Mn for polytrimethylene terephthalate is 20,000-30,000.
In the absence of an indication to the contrary, a reference to polyester is intended to include reference to copolyesters. For instance, reference to xe2x80x9cpolyalkylene terephthalatexe2x80x9d is meant also to encompass copolyesters, i.e., polyesters made using 3 or more reactants, each having two ester forming groups. For example, a copoly(ethylene terephthalate) can be used in which the comonomer used to make the copolyester is selected from the group consisting of linear, cyclic, and branched aliphatic dicarboxylic acids having 4 to 12 carbon atoms (for example butanedioic acid, pentanedioic acid, hexanedioic acid, dodecanedioic acid, and 1,4-cyclo-hexanedicarboxylic acid); aromatic dicarboxylic acids other than terephthalic acid and having 8-14 carbon atoms (for example isophthalic acid and 2,6-naphthalenedicarboxylic acid); and from linear, cyclic, and branched aliphatic diols having 3-8 carbon atoms (for example 1,3-propanediol, 1,2-propanediol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 2,2-dimethyl-1,3-propanediol, 2-methyl-1,3-propanediol, and 1,4-cyclohexanediol); and aliphatic and aromatic ether glycols having 4-10 carbon atoms (for example, hydroquinone bis(2-hydroxyethyl) ether, or a poly(ethylene ether) glycol having a molecular weight below about 460, including diethylene ether glycol). The comonomer typically can be present in the copolyester at levels in the range of about 0.5 to about 15 mole %. Isophthalic acid, pentanedioic acid, hexanedioic acid, 1,3-propane diol, and 1,4-butanediol are preferred because they are readily commercially available and inexpensive.
Copoly(trimethylene terephthalate) made from 1,3-propanediol can also be used, in which case the comonomer(s) can be selected from the above list (except the aliphatic diols having 2-8 carbon atoms may be used and ethanediol should replace 1,3-propanediol in the list). The copolyester(s) can contain minor amounts of other comonomers, and such comonomers are usually selected so that they do not have a significant adverse affect on the amount of fiber crimp (in the case of a spontaneously crimpable polyester bicomponent fibers) or on other properties. Very small amounts of trifunctional comonomers, for example trimellitic acid, can be incorporated for viscosity control.
Another preferred class of polymers are nylons. By xe2x80x9cnylonxe2x80x9d is meant one or more high molecular weight polyamide(s) which contain an amide repeat linkage in the polymer backbone. They are generally tough, translucent and semicrystalline polymers, typically processed as a melt. There are two main classes of nylon polymers, depending on the regularity of the amide linkages. In one class the formula may be written as: 
wherein R is preferably C5-C8 alkyl, most preferably (CH2)5, and wherein n is preferably about 100 to about 180. In the second class, the formula may be written as: 
wherein R is preferably C4-C10 alkyl, most preferably (CH2)4, Rxe2x80x2 is preferably C4-C12 alkyl, most preferably (CH2)6, and wherein n is preferably about 40 to about 80. When the R group has 5 carbons, the first class shown above is generally referred to as nylon 6, and is prepared by ring opening of caprolactam. When the R group has 4 carbons and the Rxe2x80x2 group has 6 carbons, the second class shown above is generally referred to as nylon 6,6, and is made by polymerizing adipic acid and hexamethylene diamine. The invention is useful with all nylons, and preferred are nylon 6, nylon 4,6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 12,12, or their copolymers and blends. Most preferred are nylon 6 and nylon 6,6, or blends thereof.
Nylon 6,6 preferably has an Mn of 10,000 or more, preferably has an Mn of 50,000 or less, preferably has Mw of 20,000 or more, and preferably has a Mw of 50,000 or less.
The polymers can be made using any technique, provided that the composition does not contain substantial amounts of anything that interferes with the goals of the invention. For instance, polytrimethylene terephthalates can be manufactured by the processes described in U.S. Pat. Nos. 5,015,789, 5,276,201, 5,284,979, 5,334,778, 5,364,984, 5,364,987, 5,391,263, 5,434,239, 5,510454, 5,504,122, 5,532,333, 5,532,404, 5,540,868, 5,633,018, 5,633,362, 5,677,415, 5,686,276, 5,710,315, 5,714,262, 5,730,913, 5,763,104, 5,774,074, 5,786,443, 5,811,496, 5,821,092, 5,830,982, 5,840,957, 5,856,423, 5,962,745, 5,990265, 6,140,543 and 6,245,844, EP 998 440, WO 00/14041, 99/54040 and 98/57913, H. L. Traub, xe2x80x9cSynthese und textilchemische Eigenschaften des Poly-Trimethyleneterephthalatsxe2x80x9d, Dissertation Universitat Stuttgart (1994), Schauhoff, S. (September 1996), xe2x80x9cNew Developments in the Production of Polytrimethylene Terephthalate (PTT)xe2x80x9d, Man-Made Fiber Year Book, and U.S. patent application Ser. Nos. 09/346,148, 09/382,970, 09/382,998, 09/500,340, 09/501,700, 09/502,322, 09/502,642, 09/503,599, and 09/505,785, all of which are incorporated herein by reference. Poly(trimethylene terephthalate)s useful as the polyester of this invention are commercially available from E. I. du Pont de Nemours and Company, Wilmington, Del. (xe2x80x9cDuPontxe2x80x9d) under the trademark Sorona.
The polymeric additive comprises repeating units having the formula: 
or salts thereof, wherein A, B and Q, which may be the same or different, are selected from aliphatic or aromatic substituents. At least four carbon atoms separate any two of the shown nitrogen groups. R is an aliphatic or aromatic group. R is inclusive of hetero atoms such as nitrogen or oxygen, may be substituted or unsubstituted, and is preferably an alkyl group of 1-8 carbon atoms, and more preferably an alkyl group of 1-4 carbon atoms. a is 1 to 5, and n is 3 to about 1,000. Preferably n is up to 100, and more preferably up to 20.
It should be understood that the polymeric additive can be polymer consisting essentially of or consisting of the repeating units shown above. Alternatively, it can be a polymer containing polymeric additive units and other polymeric units. Both types of polymeric additives are present in many instances, since when heated most of the polymeric additive will react with polymer or polymer forming compounds to form a new polymeric additive (polymer), while some of the initial polymeric additive remains unreacted. For instance, the composition prior to heating may comprise polyester and polymeric additive, and after heating such a composition may form a combination of polyester, block polymer of reacted polyester and polymeric additive, and unreacted polymeric additive. As another example additive, caprolactam and polymeric additive can form nylon and polymeric additive comprising nylon repeating units and polymeric additive repeating units.
It is preferred that four or more carbon atoms separate any two of the shown nitrogen groups, and most preferred that A and/or B comprise alkylene units having at least four carbons separating the nitrogen atoms, to obtain good thermal stability. The alkylene and arylene units of A and B may be substituted or unsubstituted, straight or branched, etc., as long as the substituent(s) and branches do not substantially interfere with dyeing or other fiber properties (e.g., the chain may contain an ether group).
The number of tertiary amines may vary from unit-to-unit and, therefore, a is an average. In one preferred embodiment, a is 1. In another preferred embodiment, a is greater than 1, preferably 2-5.
A, B and Q are preferably selected from alkylene substituents containing from 4 to 20 carbons and arylene substituents containing from 6 to 18 carbons.
Q is preferably alkylylene or arylene, such as phenylene or naphthylene. Q is preferably C4-C10, more preferably C4-C8, alkylene, and is preferably straight chain alkylene.
A and B are preferably C4-C10, more preferably C4-C8, alkylene, which are preferably straight chain alkylene.
Preferred for polyester and nylon is R is methyl. Another preferred R for nylon and polyester is isobutyl.
Any suitable synthesis may be used to prepare the polymeric additive. The polymeric additive can be prepared by polymerizing (a) polyamine containing tertiary amine unit(s) or salts thereof and (b) other monomer units (such as aliphatic and aromatic dicarboxylic acids or esters (e.g., dimethyl adipate, terephthalic acid, dimethyl terephthalate, etc.). Preferably, the polymeric additive can be prepared by polymerizing (a) polyamine containing secondary amine unit(s) or salts thereof and (b) other monomer units, followed by alkylating the secondary amine units in the resulting polyamide. The secondary amine units in the above resulting polyamide can be alkylated by methylation under acidic conditions using formaldehyde and formic acid.
In the case of a polyester, the composition may be prepared by a process comprising the steps of: (a) preparing a polymer by reacting triamine containing secondary amine or secondary amine salt unit(s) and aliphatic and aromatic dicarboxylic acid(s) or ester(s) selected from alkyl adipate, alkyl terephthalate, alkyl naphthalate or alkyl isophthalate, or mixtures thereof, or their corresponding acids, to form a secondary amine or secondary amine salt unit, (b) preparing a polymeric additive containing tertiary amine units by alkylating the secondary amine or secondary amine salt units of the polymer, and (c) mixing and heating said polymeric additive and the polyester at a temperature sufficient to form a acid-dyeable polymer composition comprising a block copolymer from some of the polyester and the unreacted polyester. The acid-dyeable polymer composition can then be dyed or formed into a shaped article and dyed. In a preferred embodiment the triamine is bis(hexamethylene) triamine and the dicarboxylic ester is dimethyl adipate.
In one embodiment of preparing the polymeric additive or compound, the triamine and second reactant are reacted at elevated temperature in the presence of water, followed by distilling off a methanol by-product, and then continuing the reaction under vacuum to form a polymer, and then alkylating the secondary amine units in the polymer chain to form the polymeric additive. In another embodiment, the process comprises or consists essentially of providing (a) the polyamine or polyamine salt and (b) dicarboxylic acid, and reacting them to form the polymeric compound. This is done without forming diester intermediate. In yet another embodiment, the process comprises providing a dicarboxylic acid, reacting the dicarboxylic acid with alcohol to form a diester (i.e., the diester analogue, such as dimethyl terephthalate}, and reacting the polyamine or polyamine salt with the diester to form the polymeric compound. Water may be used, and in one embodiment the reacting the diester with the polyamine to form the polymeric compound is carried out substantially in the absence of water. (Water from the atmosphere, as an impurity or as a minor component of an additive might be present, but it is not intentionally added in this embodiment.)
Preferably, the polyamine is selected from those having the formula:
H2Nxe2x80x94A[NRxe2x80x94B]aNH2
or salts thereof, wherein A and B, which may be the same or different, are selected from aliphatic or aromatic substituents provided that at least four carbon atoms separate any two nitrogen groups, R is an aliphatic or aromatic group, and a is 2 to 5 .
More preferably, the polyamine is selected from those having the formula:
H2N(CH2)x[NR(CH2)y]aNH2
or salts thereof, wherein x and y, which may be the same or different, are 4 to 10, a is 1 to 5, and R is an alkyl group containing 1 to 10 carbons in a straight or branched chain. Preferably, a is 1 to 4. In one preferred embodiment, a is 1. Preferred polyamines include methyl-bis(hexamethylene) triamine (x=y=6, a=1, and R=methyl), methyldibutylenetriamine (x=y=4, a=1 and R=methyl), and dimethyltributylenetetraamine (x=y=4, a=2 and R=methyl) or salts thereof, preferably they are combined with an adipate unit. In the case where the polyamine and other polymer or monomer unit are reacted and then alkylated, preferred is bis(hexamethylene)triamine, which is preferably reacted with dimethyl adipate.
The polymeric additive is preferably prepared from aliphatic and aromatic dicarboxylic acids or esters selected from the group consisting of dimethyl adipate, adipic acid, terephthalic acid, dimethyl terephthalate, dimethyl isophthalate, isophthalic acid, dimethyl naphthalate, naphthalic acid, or mixtures thereof. Preferred are dimethyl adipate and dimethyl terephthalate.
Preferred polymeric additives are poly-alkylimino-bisalkylene-adipamides, -terephthalamides, -isophthalamides, or -1,6-naphthalamides, and salts thereof. Most preferred are poly(6,6xe2x80x2-alkylimino-bishexamethylene adipamide), poly(6,6xe2x80x2-alkylimino-bistetramethylene adipamide), and poly (N,Nxe2x80x2-dialkylimino-tri(tetramethylene) adipamide, wherein the alkyl group has one to about four carbon atoms.
The molar ratio of (i) the polyamine containing a secondary or tertiary amine unit, and (ii) the one or more other monomer unit is approximately 1:1. It is preferable to add a slight excess on the order of 1 mole %-10 mole % of the polyamine (i) relative to (ii) to promote end capping of the polymeric additive composition with primary amine unit during synthesis. In this embodiment of the invention, the amine groups on the end of the polymeric additive molecule are available to form amide linkages with the polymer component of the composition. An excess of (ii), the one or more other monomer units, may also be used.
In one preferred embodiment, dimethyl adipate is combined with bis(hexamethylene) triamine to form a poly(6,6xe2x80x2-imino-bishexamethylene adipamide) which is then alkylated to form a poly(6,6xe2x80x2-alkylimino-bishexamethylene adipamide having repeat units according to the following formula: 
Therein, n is preferably at least 3 and preferably 30 or less, and R is an alkyl group containing from 1 to about 10 carbon atoms, preferably 1-6 carbon atoms and most preferably is methyl. (Prior to the alkylation step above, R was a hydrogen.) Any suitable polymeric synthesis route may be used to form the poly(6,6xe2x80x2-imino-bishexamethylene adipamide) polymer composition for use in the present invention. Any suitable alkylation method may be used to alkylate this polymer composition to the poly(6,6xe2x80x2-alkylimino-bishexamethylene adipamide) polymeric additive. Other preferred polyamides include 6,6xe2x80x2-alkylimino-bistetramethylene adipamide and N,Nxe2x80x2-dialkyliminotributylene adipamide.
The polymeric additive can be made from dimethyl adipate and bis(hexamethylene triamine) according to the following preferred procedure: Dimethyl adipate and bis(hexamethylene triamine) are reacted at elevated temperature (up to about 230xc2x0 C.), preferably in the presence of water and phosphorous acid. The methanol by-product is distilled off. Then, the reaction is continued under vacuum at about 0.2xe2x80x94about 1 mm Hg, preferably for about 30 minutesxe2x80x94about 1 hour, followed by cooling. This forms a secondary amine polymer composition. Alkylation is then carried out by reacting the secondary amine polymer composition with an alkylating agent. Preferably, the alkylation is carried out by dissolving the polymer composition in formic acid and water and reacting at an elevated temperature of about 80 to 120xc2x0 C. with formaldehyde, and removing solvent under vacuum at a temperature of about 200 to 300xc2x0 C. This forms a polymeric additive containing tertiary amine units. Alternatively, methyl-bis(hexamethylene triamine) can be made by a process such as described in the equation below and subsequently in Example 2:
xe2x80x83RNH2+2Xxe2x80x94(CH2)nxe2x80x94CN+2NaOHxe2x86x92RN[(CH2)nxe2x80x94CN]2+2H2O+2NaX
wherein R is an alkyl group having 1 to about 4 carbons, x is a halogen such as chlorine or bromine, and n is from 3 to 5. The resulting imino-bis-nitriles may then be reduced to the corresponding amines by hydrogenation over Raney cobalt catalyst, and the polymeric additive then made by polymerizing the dimethyl adipate and the resulting triamine.
The number average molecular weight (Mn) of the polymeric additive (before reaction with polymer units, such as polyester units or nylon units) is preferably at least about 1,000, more preferably at least about 3,000, and most preferably at least about 4,000, and preferably about 10,000 or less, more preferably about 7,000 or less, and most preferably about 5,000 or less. The preferred Mn depends on the polymeric additive used, the balance of the composition and the desired properties.
The polyamine, polymeric additive, composition or products made therewith can be salinized with any acid that stabilizes the amine or protects the amine group until dyeing is carried out. The acid is preferably added to the reaction mixture used to form the polymeric additive. Preferred are inorganic acids such as a phosphorus-containing acids, such as phosphorous acid, phosphoric acid, pyrophosphoric acid or phenyl phosphinic acid, most preferably phosphorous acid. However, when used with polyester compositions, preferably the amount of polymeric additive salinized with phosphorous acid is below 5 mole %, more preferably below 2 mole %, and is preferably above 1 mole % (wherein the mole % is calculated based on the total moles of tertiary amine groups in the polyamine compound).
When the polymeric additive is to be used with nylon, it is preferable to reduce the amount of phosphorous acid added to the reaction mixture for the polymeric additive. Since phosphorous acid is a catalyst for nylon polyamidation, a high level of phosphorous acid may cause a rise in pack pressure during spinning due to a molecular weight increase. With nylon, preferably the amount of polymeric additive salinized with phosphorous acid is below 1 mole % of the total (based on the total moles of tertiary amine groups in the polymeric additive). When used (with nylon), preferably the amount of polymeric additive salinized with phosphorous acid is at least 0.02 mole %, more preferably, at least 0.1 mole %, of the total (based on the total moles of tertiary amine groups in the polymeric additive).
Salinization is normally not necessary, and it is preferred not to salinize the polymeric additive or polymer composition.
The polymer composition of this invention is inclusive of unreacted polymer and polymeric additive.
Preferably the polymer composition is prepared by melt blending the polymeric additive and the polymer. The temperature should be above the melting points of each component but below the lowest decomposition temperature, and accordingly must be adjusted for any particular composition of polymer and polymeric additive. The polymer and polymeric additive may be heated and mixed simultaneously, pre-mixed in a separate apparatus before the heating occurs, or alternately may be heated and then mixed. Further, the polymer composition may be formed and then used, or may be formed during use (e.g., by mixing and heating chips or flakes of polymer and polymer additive in an extruder at a fiber or film manufacturing facility, or by blending molten polymer and polymeric additive in fiber or film manufacture.) Melt blending is preferably carried out at about 200 to about 295xc2x0 C., most preferably about 260xe2x80x94about 285xc2x0 C., depending on the polymer. For polytrimethylene terephthalate, the preferred temperatures are about 230 to about 270xc2x0 C., most preferably about 260xc2x0 C. For polyethylene terephthalate, the preferred temperatures are about 200 to about 295xc2x0 C., most preferably about 280xe2x80x94about 290xc2x0 C. For polybutylene terephthalate, the preferred temperatures are about 200 to about 295xc2x0 C., most preferably about 250xe2x80x94about 275xc2x0 C. For nylon 6,6, the preferred temperatures are about 200 to about 295xc2x0 C., most preferably about 280xe2x80x94about 290xc2x0 C. For nylon 6, the preferred temperatures are about 200 to about 295xc2x0 C., most preferably about 260xe2x80x94about 275xc2x0 C.
As noted previously, the polymer and the polymeric additive can react. Since there is more polymer than polymeric additive, the composition comprises polymeric additive comprising polymer and polymeric additive repeat units and unreacted polymer. In many instances it will also contain polymeric additive that has no units from the polymer.
When polyester and polymeric additive are reacted, the polymer and polymeric additive form a block copolymer by reacting at their ends. By block copolymer, for example with reference to the poly(6,6xe2x80x2-alkylimino-bishexamethylene adipamide) polymeric additive and polytrimethylene terephthalate, reference is to a polymer formed by the polyester joined to the polymeric additive by a covalent bond. In corresponding nylon compositions, a random copolymer can be formed when the mixing time is long because of transamidation reactions.
The polymeric additive can also be added to the reactants used to form the polymer and, then, when the polymer is formed some of the polymer will contain units derived from polymeric additive. This can result in block or random polymers being formed with polymeric additive as a unit in the chain.
The polymer composition contains an effective amount of polymeric additive containing a tertiary amine unit to promote acid-dyeability. The particular amount of polymeric additive used depends on the polyester or nylon compositions; the polymeric additive used, particularly the nature and amount of tertiary amines; the acid dye used. The preferred amount of polymeric additive can be calculated based on the amount of tertiary amine of the polymeric additive in the composition. Very small amounts of the polymeric additive are needed when it is desired to make minor corrections to the dye depth achieved by the polymer. In such instances the composition can contain as little as about 6 moles tertiary amine/per million grams of the resulting polymer (mpmg). When more than minor changes are desired, the composition preferably contains about 44 or more moles tertiary amine/per million grams of the resulting polymer (mpmg), even more preferably about 88 or more mpmg, and most preferably about 132 mpmg or more, and preferably the composition contains up to about 480 mpmg, more preferably up to about 322 mpmg and most preferably up to 240 mpmg. In the case of polytrimethylene terephthalate with the preferred polymeric additive prepared from Me-BHMT, the composition preferably contains at least about 48 mpmg, more preferably at least about 96 mpmg, and most preferably at least about 144 mpmg. For nylon 6,6 mixture with Me-BHMT polymeric additive, the tertiary amine content is preferably at least 44 mpmg and preferably no more than 88 mpmg.
The amount of polymeric additive needed to reach a particular addition level depends on the nature of the polymeric additive. For example, to reach 44 mpmg tertiary amine group with nylon 6,6 and Me-BHMT, it is necessary to add 1 mole (325.5 g) Me-BHMT polymer into 22,406 g nylon 6,6. When a is 2, for instance with dimethyltributylenetetramine, 0.5 mole of that polymer will give us 44 mpmg tertiary amine group in the resulting polymer.
It is believed that when linear polymer forming conditions are employed and the polyester (e.g., polyalkylene terephthalate) or nylon and the polymeric additive are mixed and heated to form a composition, the primary amine functional group at the end of the triamine molecule portion of the polymeric additive reacts to form an amide linkage with carboxyl groups of the polyester or nylon, leaving the tertiary amine unit portion of the triamine essentially unreacted and free to form a dye site. Thus the tertiary amine units become a part of the polymer chain and their presence in the polymer (e.g., polyester or nylon) fiber formed from the acid-dyeable compositions of the invention is permanent and not easily removed by washing, dry cleaning or other processes used to launder fabric articles.
The acid-dyeable polymer composition of the invention typically does not discolor and/or thermally degrade. This is especially advantageous when the polyester or nylon composition is thermally processed, for example by extrusion from the melt, into shapes such as films, fibers or membranes. The dyed articles are superior in color fastness, brightness, weather resistance, wear resistance and oxidation stability.
The polyester or nylon composition of the invention may be used to produce, acid-dyeable shaped articles, including high strength shaped articles. For example, in particular embodiments of the invention wherein the polyester is polytrimethylene terephthalate, melt-spun filaments having a tenacity of 2.0 g/d or more and a dye exhaustion of 30%-90% or higher, preferably 60%-95% or higher, are obtained. This is quite remarkable because polytrimethylene terephthalate is generally considered a difficult polyester to spin into high strength fibers or filaments. An added difficulty is that the use of additives to enhance one property of a polymer, e.g., acid-dyeability, often negatively affects other properties such as processability and strength. However, in accordance with the invention, acid-dyeable, high strength polyalkylene terephthalates, for example poly(trimethylene) terephthalate, fibers are obtained.
Other additives may be added to the acid-dyeable polyester compositions of this invention to improve strength or facilitate post extrusion processing. For example, hexamethylene diamine and/or polyamides such as nylon 6 or nylon 6,6 may be added in minor amounts (e.g., about 0.5-about 5 mole %) to add strength and processability.
The polymer composition can, if desired, contain various other additives, e.g., antioxidants, delusterants (e.g., TiO2, zinc sulfide or zinc oxide), colorants (e.g., dyes or pigments), stabilizers, flame retardants, fillers (such as calcium carbonate), antimicrobial agents, antistatic agents, optical brightners, extenders, processing aids, viscosity boosters, toning pigments and other functional additives. TiO2 may be added to the polymer or fibers.
The compositions of this invention are useful in fibers, fabrics, films and other useful articles, and methods of making such compositions and articles. By xe2x80x9cfibersxe2x80x9d, reference is made to items recognized in the art as fibers, such as continuous filaments, staple, and other chopped fibers. The fibers may be monocomponent (sometimes also referred to as xe2x80x9chomofibersxe2x80x9d), or bicomponent or other multicomponent fibers, including sheath-core, eccentric sheath-core, and side-by-side fibers, and yarns made therefrom. Fabrics include knitted, woven and nonwoven fabrics. The compositions may form a film or a film layer, etc.
Bulked continuous filaments and fabrics may be manufactured according to the process described in U.S. Pat. Nos. 5,645,782 and 5,662,980, which are incorporated herein by reference. Other documents describing fibers and fabrics, and their manufacture, include U.S. Pat. Nos. 5,885,909 and 5,782,935, WO 99/06399, 99/27168, 99/39041, 00/22210, 00/26301, 00/29653, 00/29654, 00/39374 and 00/47507, EP 745 711, 1 016 741, 1 016 692, 1 006 220 and 1 033 422, British Patent Specification No. 1 254 826, JP 11-100721, 11-107036, 11-107038, 11-107081, 11-189920, and 11-189938, U.S. patent application Ser. Nos. 09/518,732 and 09/518,759, and H. L. Traub, xe2x80x9cSynthese und textilchemische Eigenschaften des Poly-Trimethyleneterephthalatsxe2x80x9d, Dissertation Universitat Stuttgart (1994), H. L. Traub xe2x80x9cDyeing properties of Poly(trimethylene terephthalate) fibresxe2x80x9d, Melliand (1995), H. L. Traub et al., xe2x80x9cMechanical Properties of fibers made of polytrimethylene terephthalatexe2x80x9d, Chemical Fibers International (CFI) Vol. 45,110-111 (1995), W. Oppermann et al. xe2x80x9cFibers Made of Poly(trimethylene terephthalate)xe2x80x9d, Dornbirn (1995), H. S. Brown, H. H. Chuah, xe2x80x9cTexturing of Textile Filament Yarns Based on Poly(trimethylene terephthalate)xe2x80x9d, Chemical Fibers International, 47:1, 1997. pp. 72-74, Schauhoff, S. xe2x80x9cNew Developments in the Production of Polytrimethylene Terephthalate (PTT)xe2x80x9d, Man-Made Fiber Year Book (September 1996), all of which are incorporated herein by reference.
The acid-dyeable polyester compositions can be used to make acid-dyeable polyester bicomponent fibers, for example, bicomponent fibers comprising poly(ethylene terephthalate) and poly(trimethylene terephthalate) or poly(ethylene terephthalate) and poly(tetramethylene terephthalate). Bicomponent fibers based on poly(ethylene terephthalate) and poly(trimethylene terephthalate) are preferred. The polymeric additive can be incorporated into either or both components. The components can be arranged in a sheath-core, eccentric sheath-core, or side-by-side relationship. When it is desired that the bicomponent fiber be crimpable on drawing, heat-treating, and relaxing to form a stretchable fiber, an eccentric sheath-core or side-by-side relationship can be used; side-by-side is preferred for higher crimp levels. The preferred polyethylene terephthalate/polytrimethylene terephthalate bicomponent fibers can be manufactured as described in copending U.S. patent application Ser. No. 09/758,309 (Docket No. LP4440-CIP1), which is incorporated herein by reference. One or both of the polyesters used in these bicomponent fibers can be copolyesters. Comonomers useful in such copolyesters are described previously. The comonomer can be present in the copolyester at a level in the range of about 0.5 to 15 mole percent.
Acid dyeing is carried out using conventional techniques, such as those used for nylon. The polymer compositions, fibers, films, yarns, fabrics, membranes, etc., may be acid dyed.
The polymer composition, or fibers, films, yarns, fabrics, membranes and other useful shaped articles can be acid dyed to a dye exhaustion of about 30%-about 90% or higher, preferably about 60%-about 95% or higher.
The acid-dyeable polymer compositions according to the present invention contain tertiary amines and are basic compounds. As such, they have a relatively high affinity for acid dyes and can be dyed in a range of colors. For example, the acid dyeable polyester compositions may be spun into fibers and dyed with C.I. Acid Blue 25 (C.I. 62055), C.I. Acid Red 4 (C.I. 14710), C.I. Acid Yellow 40 (C.I. 18950), C.I. Acid Green 25 (C.I. 61570), Tectilon Yellow 2G, Tectilon Red 2B, Tectilon Blue 4R, Lanaset Yellow 2R, Lanaset Red 2B, Lanaset Blue 2R and Irgalan premetallized acid dyes either alone or in combination. (These dyes are available from Ciba Specialty Chemicals Corporation, High Point, N.C. (Ciba).) Acid dye conditions according to the invention are preferably from a pH of 3.5 or more, and a pH of 4.5 or more is especially preferred ranging up to a pH of about 6.5. Of course, lower pH values, e.g., 3.0, may be used if desired.
The invention is further directed to the acid-dyed polymer composition prepared by acid dyeing any of the acid-dyeable polymer compositions described above, and to a process comprising (1) providing the acid-dyeable polyester or nylon composition and (2) acid dyeing the composition, as well as acid-dyed fibers, film, yarn, fabric, membrane, etc.
Intrinsic Viscosity
Intrinsic viscosity (IV) was determined using viscosity measured with a Viscotek Forced Flow Viscometer Y900 (Viscotek Corporation, Houston, Tex.) for the polyester dissolved in 50/50 weight % of trifluoroacetic acid/methylene chloride at a 0.4 grams/dL concentration at 19xc2x0 C. following an automated method based on ASTM D 5225-92. These measured IV values were correlated to IV values measured manually in 60/40 weight % of phenol/1,1,2,2-tetrachloroethane, following ASTM D 4603-96.
Relative Viscosity
Relative Viscosity (RV) for polymer and fibers was determined using viscosity measured with a Viscotek Model Y900 forced flow viscometer by dissolving the polymer (fiber) in 90% formic acid at 25xc2x0 C. The relative viscosity is presented as the ratio of the viscosity of a 8.4% (wt/wt) solution of the polymer in 90% formic acid to the viscosity of pure 90% formic acid.
A: Tectilon Acid Dyes in the Presence of Carrier
The as-spun yarn was knitted into a sock sample. A 5 gram sock sample was put into a scouring solution containing 2 weight % Merpol HCS nonionic surfactant (DuPont) and 1 weight % acetic acid at 72xc2x0 C. for 20 minutes. The sample was rinsed and placed into a 100 ml dye-bath containing 1 weight % of either Tectilon yellow 2G, Tectilon red 2B or Tectilon blue 4R and 0.5% Tanalon HIW carrier (Sybron Chemicals, Birmingham, N.J.) at pH 3. The dye bath was heated to 100xc2x0 C. for 90 minutes. The sample was then rinsed with water and treated with 4% Erional PA solution (Ciba Corporation, Greensboro, N.C.) at pH 4.5-5.0 at 82xc2x0 C. for 20 minutes for dye fixing. The remaining dye solution was measured in a visible spectrometer to calculate the exhaust.
Tectilon acid dyes were also run without a carrier in an identical manner to that above.
B: Lanaset Acid Dyes in the Absence of Carrier
The as-spun yarn was knitted into sock sample. A 5 gram sock sample was put into a scouring solution containing 2% Merpol HCS and 1% acetic acid at 72xc2x0 C. for 20 minutes. The sample was rinsed and placed into a 100 ml dye bath containing 2% of either Lanaset Yellow 2R, Lanaset Red 2B, or Lanaset Blue 2R at pH 3. The dye bath was heated to 100xc2x0 C. for 90 minutes. The sample was then rinsed with water and treated with 4% Erional PA solution at pH 4.5-5.0 at 82xc2x0 C. for 20 minutes for dye fixing. The remaining dye solution was measured in a visible-range spectrometer to calculate the exhaust.
Tensile testing was carried out at 70xc2x0 F. (21xc2x0 C.), relative humidity 65%, on an Instron type tensile tester. Yarn samples were twisted 3 turns per inch and were tested at a crosshead speed of 3.6 inches/minute at a gauge length of 6 inches. Five samples were run for each item tested.